May I ask what country you live in, and what area of that country?

How about inviting them over at a specific time for some tea or coffee?

Do you have their cell numbers? If so, you can text one of them or do a group text with both of them and ask them “Are you guys free tonight? Do you want to hang out” or “If you aren’t doing anything tomorrow night, I we can hang out” or something like that. “If you’re watching the game and want company, I’m free.” Those are some examples you can text.

What kind of area do you live in? Apartments, houses, townhouse?
The reason I ask is that something that seems to bring people together is yard or garage sales. I know it sounds strange, but I’m not very outgoing, but when neighbors have had yard sales, I will walk over and browse and then conversations start and I have gotten to be friends with them. It’s the middle of winter here in the states, so now isn’t an ideal time.

I don’t know your living situation. Around here the best way would be to ask for some temporary help with a project that goes 3 times faster and is 4x safer, with 2 people. For example: cutting a tree down, moving a log splitter, pulling your car out of the snow, fixing your mailbox post, removing a large tree branch, holding the ladder while going up on the roof to clean the gutters.
After the short task is done, thank them profusely and offer to do the same for them. Show up the next day with a bottle of wine, or cookies, or pizza or as a thank you gesture.

I think it is wonderful that you are doing this. In the words of Mr Rogers: “Won’t you be, won’t you be, won’t you be my neighbor.”

See if you guys have anything in common like painting or home improvements. I have a few family members that like Bingo (boring) maybe they will like that. Invite them over for movie nights on Fridays or something.

Another vote for a coffee meet-up or game night, perhaps. It IS hard with neighbors but popping by or excuses could be intrusive. Good luck!

@KNOWITALL I agree. I have neighbors who over the course of a few years became friends but because we live so close, I am careful not to just drop in. I always text if I want to come by to see if it is a good time. Of course, another country or part of the US could have different cultural norms.

While they may enjoy your company when you visit, they might just be polite and might not wish to become friends. I live in an apartment and am very hesitant to be friendly or to do more than say ‘hello’. Some people don’t know the social graces and will simply knock on your door on a whim, and if they see your car, they know you’re home. It can become awkward. I’m a very private person and don’t want anyone in my apartment unless I invite them in. I feel upset and forced to allow them in if they show up (I know, that’s my issue, but it is an issue). I’m not saying these people you’re talking about are like that, but it’s something to consider.

I noticed that the suggested tasks that needed extra help were all outdoor related and might not apply to your situation. Here are some indoor tasks that might: hanging a new curtain rod or blinds, moving something from the attic or basement, moving the refrigerator.
Apologetically ask for help, and graciously thank your neighbor for assisting.
If you are doing something dangerous like using a table saw, skill saw, nail gun etc.ask your neighbor if they would be willing to be the DD, Designated Dialer for 911, in case something goes awry. The request is good for a laugh and certainly breaks the ice. And gives you both something to talk about later.

Another idea is you can invite them over to your house. If you’re watching the game, or if you want to use an excuse like “I made a bunch of chicken wings, if you guys are hungry, please feel free to stop over” or “if you both want to stop by, I’m streaming __________ tonight and I heard it’s supposed to be good.”

Not everyone want to be “friends” with their neighbors. I am one of them. I am friendly with my neighbors and stop and say hello and chat for a few minutes, but I am not and don’t want to become friends. That way we know each other enough to get help if needed but no one expects to have their morning coffee in my kitchen.

@SnipSnip: From the OP’s details, the neighbors like when they (the OP) visit. If the neighbors are not interested in furthering the friendship, they can just say “no thanks.” The OP won’t know unless they (the OP) asks.

“Just dropping in” isn’t a good idea at this stage. Why not ask them round for a meal some evening and see how it goes. While your neighbours may be delighted by your company they may feel that dropping in unannounced is an invasion of their privacy.

Things like this take time to form. Don’t press it. Just allow it all to happen naturally. If it is mutual it will show.